High vacuum ball valve

ABSTRACT

A ball valve having a valve stem assembly disposed within a valve body through-hole. The valve body through-hole is encircled with secondary bores to accommodate components of the valve stem assembly. The valve stem assembly includes an upper bearing and lower bearing, which are seated into corresponding secondary bores and a stem seal that seats within a stem seal gland. The upper bearing further includes a step that interdigitates with the stem seal gland to form a stem seal groove when the valve stem assembly is disposed within the through-hole.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. ProvisionalApplication Ser. No. 61/285,585, filed Dec. 11, 2009, which is herebyincorporated by reference herein in its entirety, including any figures,tables, or drawings.

BACKGROUND OF INVENTION

A ball valve is one of several types of “quarter-turn” closing valves.Such valves are usually held between two sealed connections and operateby the turning of a ball inside a valve body. The ball has a throughhole or port that can be lined up with the open ends of the valve topermit flow. When the ball is turned, by an attached handle or otheractuator, the port becomes smaller and blocks flow through the valve.Usually, if the ball is turned a full 90°, the port becomesperpendicular to the ends of the valve and blocks flow entirely.Variations can utilize a ball with more than one port, such that whenthe valve is turned, flow is redirected through a different valve andfurther turning can close off flow entirely. Larger valves with heavierballs, such as those used on pipelines or water mains may additionallyuse trunnions to help support the ball and prevent damage to internalcomponents.

Ball valves are desirable for use in industry because they enable quickopening and a leak-proof closed seal. However, ball valves used inindustrial applications are often exposed to various chemical compounds,liquid or gaseous, that can have a corrosive effect on the components,which can compromise the internal seals. It is not unusual for ballvalves used in industry to be exposed to excessive temperatures (below0° F. to over 1000° F.) and pressure (10⁻¹⁰ mm Hg to over 100 PSI). Mostoften, the seals between the central valve stem and the stem seal arethe most vulnerable. A common implementation of stem seals to thoseskilled in the art is an o-ring. For the purposes of this discussion,the terms stem seal and o-ring are interchangeable.

Elevated temperatures are particularly problematic and can have thegreatest effect because of expansion of the stem seal material. Variousspecialized metallic or elastomeric materials have been developed towithstand the chemical or environmental extremes for each application.Valve body designs have also been improved to accommodate for stem sealexpansion within the valve gland. Nonetheless, extrusion of the stemseal material into surrounding spaces during temperature-inducedexpansion is still a problem. Further, it can have a deleterious effectnot only on the integrity of the stem seal, but on the surroundingcomponents with which the expanding stem seal material comes intocontact.

As technology changes and develops, ball valves are increasinglyutilized in a greater variety of industrial applications. As such, it isnecessary for ball valve seals to withstand a multitude of conditions,including even greater temperature extremes and corrosive conditions.There is a need for a ball valve design capable of withstanding hightemperature and high pressure conditions with minimal or no leakage.More particularly, there is a need for a ball valve design that canprovide the necessary leakage control at different temperatures andaccommodate for temperature- or chemical-induced expansion of stem sealmaterials.

BRIEF SUMMARY

Embodiments of the subject invention pertain to a ball valve withimproved leak-proof components. A specific embodiment pertains to a ballvalve that can utilize non-metallic materials and an improved valve bodyto achieve leak-proof seals around the valve stem and valve body.Embodiments of the subject ball valve can utilize non-metallic upperbearings and lower bearings and an improved stem seal seated in a valvegland to achieve a leak-proof seal. Advantageously, ball valves inaccordance with the subject invention can be configured for use in avariety of applications by changing the material(s) utilized for thestem seal.

More specific embodiments can include a stem seal positioned within avalve gland having dimensions that significantly eliminate or reduceextrusion of the stem seal material between the valve stem and valvebody and provide ideal compression of the stem seal. Still otherembodiments have an upper bearing that can include a counter-sunk lipthat extends into the gland. Further embodiments can include a lowerbearing cup that can fit over the lower end of the valve stem tostabilize the valve stem and prevent lateral movement of the lowerportion of the valve stem.

Thus, embodiments of the subject invention provide a ball valve withincreased resistance to temperature- or chemical-induced stem sealleakage. The advantages of various embodiments of the subject ball valveinclude, but are not limited to, the ability of the valve gland andsurrounding bearings to confine the stem seal and prevent improperextrusion into surrounding spaces and to stabilize the valve stem andreduce lateral stem movement.

Various embodiments of a valve in accordance with the subject invention,such as embodiments shown in FIGS. 1A, 7A-7F, and 8A-8B, can incorporatea valve body, where the valve body has a through hole that passesthrough a wall of the valve body from an outer wall surface to an innerwall surface. The proximal end of the through hole is an opening in theinner wall surface and a distal end of the through hole is an opening inthe outer wall surface. The through hole can have a body gland sectionpositioned proximal to the outer wall surface, where the body glandsection has a circular cross-section having a first radius. The throughhole also can have a body midsection having a circular cross-sectionhaving a second radius. Note, FIG. 7E shows an embodiment without a bodymidsection. The through hole also has a lower seat positioned betweenthe body midsection and the inner wall surface, where at least a portionof the lower seat has a third radius, such that the second radius issmaller than the first radius and the second radius is smaller than thethird radius.

The valve also incorporates a valve stern, where the valve stem has ahead proximate a proximal end of the valve stem, a stem midsectionhaving a circular cross-section, and a stem gland section. The stemmidsection is between the head and the stem gland section. Note, FIG. 7Eshows an embodiment without a stem midsection. At least a portion of thestem gland section has a circular cross-section, such that the stem sealis in contact with a portion of the stem glad section having a circularcross-section. Preferably, the entire stem gland section has a circularcross-section. The valve body and the valve stem are adapted such that adistal end of the valve stem can enter the proximal end of the throughhole and pass into the through hole such that at least a portion of thehead is in the lower seat. At least a portion of the head has a headradius that is larger than the second radius, which prevents the stemfrom passing all the way through the through hole. The head and thelower seat are adapted such that a lower bearing cup can be positionedsuch that the lower bearing cup prevents contact between a head outersurface and a lower seat inner surface when the valve stem is fullyinserted into the through hole. FIGS. 1A and 8A-8B show embodimentsusing various shaped lower bearing cups. The stem gland section and thebody gland section are adapted such that a stem seal can be positionedaround the stein gland section so as to be in contact with a stem glandsection outer surface around a circumference of the stem gland sectionand, when the valve stem is fully inserted into the through hole, thestem seal is positioned in a stem seal gland. The stem seal gland isformed by the stem gland section outer surface, a body gland sectioninner surface, a proximal stem seal gland face, and a distal stem sealgland face. The proximal stem seal gland face is a distal face surfaceof the body midsection. For case of description, when describing thevarious surfaces of the sections of the valve stem, the through hole,the lower bearing cup, and the upper seal, (i) outer edge surface canrefer to a surface having at least a portion facing at least partiallyto the outside of the part. In specific embodiments, some outer edgesurfaces have a normal that is substantially perpendicular, if notperpendicular, to the longitudinal axis of the stem and to thelongitudinal axis of the through hole, (ii) inner edge surface issimilar to outer edge surface but faces in toward the longitudinal axisof the through hole and/or the longitudinal axis of the stem, (iii) facecan refer to a surface of a part that has at least a portion that facesat least partially toward the distal or proximal direction, where adistal face is at the distal end of the part and a proximal face is atthe proximal end of the part. In specific embodiments, some faces havenormals that are substantially parallel, if not parallel, to thelongitudinal axis of the through hole and/or stem. When (i) the valvestem is fully inserted into the through hole, (ii) the stem seal ispositioned around the stem gland section so as to be in contact with thestem gland section outer surface around a circumference of the stemgland section, (iii) the stem seal is positioned in the stem seal gland,and (iv) a pressure differential is applied between a first regiondistal to the outer wall surface and a second region proximal to theinner wall surface such that a first pressure of the first region ishigher than a second pressure of the second region, a first seal iscreated between the stem seal and the stem gland section outer surfaceand a second seal is created between the stem seal and the body glandsection inner surface. The creation of the first and second sealmaintains the pressure differential between the first region distal tothe outer wall surface and the second region proximal to the inner wallsurface. The first seal and the second seal are maintained as the valvestem is rotated about a longitudinal axis of the valve stem with respectto the valve body.

The lower seat can have a variety of cross-sectional shapes, dependingon the shape of the lower bearing cup, and preferably has a circularcross-section. In a specific embodiment, when the distal end of thevalve stem enters the proximal end of the through hole and passes intothe through hole such that at least a portion of the head is in thelower seat, the distal end of the valve stem extends past the outer wallsurface. This can allow a handle or other mechanism to interconnectwith, and rotate, the stem.

Although the head outer surface can have a variety of shapes, in aspecific embodiment, the head outer surface has a head face and a headouter edge surface, and the lower seat inner surface has a lower seatface and a lower seat inner edge surface, such that the lower bearingcup prevents contact between the head face and the lower seat face andprevents contact between the head outer edge surface and the lower seatinner edge surface when the valve stem is fully inserted into thethrough hole.

The lower bearing cup can have a face portion and an edge portion, suchthat when the valve stem is fully inserted into the through hole thelower bearing cup is positioned so as to prevent contact between thehead face and the lower seat face and to prevent contact between thehead outer edge surface and the lower seat inner edge surface, whereinthe edge portion contains lateral movement of the head with respect tothe lower seat. The edge portion keeps lateral movement of the head withrespect to the lower seat to below or equal to a maximum lateralmovement, wherein lateral movement above the maximum lateral movementleads to improper extrusion of the stem seal between the stem glandsection outer surface and the proximal stem seal gland face. This isbecause if too large a lateral movement is allowed between the head andthe lower seat, where lateral movement is perpendicular to thelongitudinal axis of the stem and/or the longitudinal axis of thethrough hole, the stem seal will extrude between the stem and the valvebody, which tends to break the seal. In a specific embodiment, whereinthe head has a circular cross-section having a head radius, the lowerseat has a circular cross-section having the third radius, and thedifference between the head radius and the third radius is less than orequal to a thickness of the edge portion of the lower bearing cup plusthe maximum lateral movement.

A specific embodiment relates to a ball valve, where the valve stem hasa protrusion extending proximally from the head such that when the valvestem is fully extended into the through hole the protrusion extendsproximally past the inner wall surface and engages the ball such thatwhen the valve stem is rotated about a longitudinal axis of the valvestem the ball rotates.

In a specific embodiment, such as shown in FIG. 7A, the through hole canhave an upper section having a circular cross-section having a fourthradius, where the upper section is distal to the body seal glandsection, the fourth radius is the same as the second radius, and aproximal face of the upper section is the proximal stem seal gland face.In other embodiments, the fourth radius is not the same as the secondradius.

An upper bearing can be positioned between the stem and the valve bodyat a position distal to the stem seal when the valve stem is fullyinserted into the through hole and the pressure differential is applied.The upper bearing, in combination with the lower bearing cup, preventscontact between the valve stem and the through hole. The upper bearing,in combination with the lower bearing cup, can also maintain the stemseal gland in a proper position to avoid improper extrusion of the stemseal.

The through hole can have an upper seat, where the upper seat has aradius at least as large as the second radius at each position around acircumference of the upper seat, where at least a portion of the upperbearing is positioned in the upper seat when the valve stem is fullyinserted into the through hole. The upper seat can provide a place forall or a portion of an upper bearing and can provide a structure toprevent the upper bearing from allowing too much lateral movement of thestem relative to the valve body above the stem seal. In an embodiment,the upper bearing in combination with the lower bearing cup preventscontact between the valve stein and the through hole as the valve stemis rotated up to 90 degrees about a longitudinal axis of the valve stem.In specific embodiments, such as shown in FIG. 1A, at least a portion ofa proximal face of the upper bearing is the proximal stem seal glandface. The upper bearing can have a main upper bearing body and a step ata proximal end of the upper bearing. The step can be positioned in thebody gland section when the valve stem is fully inserted into thethrough hole such that an outer edge surface of the step contacts aportion of an inner radial surface of the body gland section that iscontinuous with an inner radial surface of the stem seal gland, whereina proximal face of the step is the distal stem seal gland face. FIG. 1Ashows such an embodiment.

The step, in combination with the lower bearing cup, can prevent contactbetween the stem midsection outer surface and a body midsection innersurface by keeping lateral movement of the stem with respect to the bodygland section to below or equal to a maximum lateral movement. Lateralmovement above the maximum lateral movement can lead to improperextrusion of the stem seal between the stem gland section outer surfaceand the proximal stem seal gland face and should be avoided. In aspecific embodiment, the step has an annular cross-section having aninner step radius and an outer step radius, where the difference betweenthe inner step radius and a radius of a section of the stem thatcontacts the step plus the difference between the first radius and theouter step radius is less than or equal to the maximum lateral movement.

Referring to FIG. 7E, an embodiment without a body midsection or a steinmidsection is shown. The valve has a valve body, with the valve bodyhaving a through hole that passes through a wall of the valve body froman outer wall surface to an inner wall surface. A proximal end of thethrough hole is an opening in the inner wall surface and a distal end ofthe through hole is an opening in the outer wall surface. The throughhole has a body gland section positioned proximal to the outer wallsurface, where the body gland section has a circular cross-sectionhaving a first radius, and a lower seat positioned between the bodygland section and the inner wall surface, where at least a portion ofthe lower seat has a second radius, and the second radius is larger thanthe first radius. The valve also has a valve stem, where the valve stemhas a head proximate a proximal end of the valve stem, and a stem glandsection, where at least a portion of the stem gland section has acircular cross-section, and the stem gland section is distal to thehead. The valve body and the valve stem are adapted such that a distalend of the valve stem can enter the proximal end of the through hole andpass into the through hole such that at least a portion of the head isin the lower seat. At least a portion of the head has a head radius thatis larger than the first radius. The head and the lower seat are adaptedsuch that a lower bearing cup can be positioned such that the lowerbearing cup prevents contact between a head outer surface and a lowerseat inner surface when the valve stem is fully inserted into thethrough hole. The stem gland section and the body gland section areadapted such that a stem seal can be positioned around the stem glandsection so as to be in contact with a stem gland section outer surfacearound a circumference of the stem gland section and when the valve stemis fully inserted into the through hole the stem seal is positioned in astem seal gland, wherein the stem seal gland is formed by the stem glandsection outer surface, a body gland section inner surface, a proximalstem seal gland face, and a distal stem seal gland face. When (i) thevalve stem is fully inserted into the through hole, (ii) the stem sealis positioned around the stem gland section so as to be in contact withthe stem gland section outer surface around a circumference of the stemgland section, (iii) the stem seal is positioned in the stem seal gland,and (iv) a pressure differential is applied between a first regiondistal to the outer wall surface and a second region proximal to theinner wall surface such that a first pressure of the first region ishigher than a second pressure of the second region, a first seal iscreated between the stem seal and the stem gland section outer surfaceand a second seal is created between the stem seal and the body glandsection inner surface. The first and second seal maintain the pressuredifferential between the first region distal to the outer wall surfaceand the second region proximal to the inner wall surface. The first sealand the second seal are maintained as the valve stem is rotated about alongitudinal axis of the valve stem with respect to the valve body.Again, in a specific embodiment, the head outer surface can have a headface and a head outer edge surface, and the lower seat inner surface hasa lower seat face and a lower seat inner edge surface, such that thelower bearing cup prevents contact between the head face and the lowerseat face and prevents contact between the head outer edge surface andthe lower seat inner edge surface when the valve stem is fully insertedinto the through hole. In a specific embodiment, such as shown in FIG.7E, the lower bearing cup provides the proximal stem seal gland face.

In specific embodiments, the lower bearing cup, in combination with anupper bearing, can constrain lateral movement of the head of the stemwith respect to the lower seat and constrain lateral movement of thestem with respect to the valve body, above the stem seal, so as to limitrotation of the stem with respect to the valve body such that the anglebetween the longitudinal axis of the stem and the longitudinal axis ofthe valve body is maintained less than 5°, maintained less than 4°,and/or maintained less than 3°. In order to accomplish this, tolerancesfor the lower bearing cup, upper bearing and parts in contact with thesame can be less than or equal to 0.004 inches.

BRIEF DESCRIPTION OF DRAWINGS

In order that a more precise understanding of the above recitedinvention can be obtained, a more particular description of variousembodiments of the subject invention will be rendered by reference tospecific embodiments thereof that are illustrated in the appendeddrawings. It should be understood that the drawings presented herein maynot be drawn to scale and that any reference to dimensions in thedrawings or the following description are specific to the embodimentsdisclosed. Any variations of these dimensions that will allowembodiments of the subject invention to function for its intendedpurpose are considered to be within the scope of the subject invention.Thus, understanding that these drawings depict only typical embodimentsof the invention and are not therefore to be considered as limiting inscope, embodiments of the invention will be described and explained withadditional specificity and detail through the use of the accompanyingdrawings in which:

FIG. 1A is a front cross-sectional view of one embodiment of the subjectinvention with the valve stem assembly seated within a valve body.

FIG. 1B is a perspective view of one embodiment of the valve body of thesubject invention.

FIGS. 2A and 2B are a top plan view of one embodiment of the upperbearing of the subject invention.

FIGS. 3A, 3B-1, 3B-2, and 3C are a perspective view, front elevationview, a distal end plan view, and a right side elevation view,respectively, of one embodiment of the valve stem of the subjectinvention.

FIGS. 4A and 4B are a partial cut-away and an enlarged cross-sectionalview, respectively, of a valve body that can be utilized withembodiments of the subject invention. FIG. 4A shows the right side ofthe valve body partially cut-away to reveal the structure of the throughhole in the valve body. FIG. 4B is an enlarged view of encircled portion“A” in FIG. 4A showing through hole structure in more detail.

FIGS. 5A and 5B are a front elevation view and a cut-away view throughline A-A of a right side elevation, respectively, of the lower bearingof one embodiment of the subject invention.

FIG. 6 is a photograph of a typical stem seal that can be used withembodiments of the valve stem assembly of the subject invention.

FIGS. 7A-7F show various embodiments of the subject invention thatmodify one or more aspects of the embodiment shown in FIG. 1A.

FIGS. 8A and 8B show two embodiments similar to the embodiment shown inFIG. 1A, where the shape of the lower bearing cup, head of the valvestem, and the lower seat have been modified with respect to theembodiment shown in FIG. 1A.

DETAILED DISCLOSURE

Embodiments of the subject invention pertain to devices and methods forachieving a leak-proof valve stem assembly. More specifically, theembodiments of the subject invention pertain to a valve stem assemblythat can be utilized at temperatures between approximately 20° C. and200° C. without leakage of the various components.

The following description will disclose embodiments that areparticularly useful in the field of quarter-turn valve assemblies, inparticular ball valve devices. However, a person with skill in the artwill be able to recognize numerous other uses for which the embodimentsof the subject invention would be applicable. While the subjectapplication describes a particular use in ball valve devices, othermodifications apparent to a person with skill in the art and havingbenefit of the subject disclosure are contemplated to be within thescope of the embodiments of the present invention.

Also, as used herein, and unless otherwise specifically stated, theterms “operable communication” and “operably connected”, or the like,means that the particular elements are connected in such a way that theycooperate to achieve their intended function or functions. The“connection” may be direct, or indirect, physical or remote.

In addition, references to “first”, “second”, and the like (e.g., firstand second surface), as used herein, and unless otherwise specificallystated, are intended to identify a particular feature of which there areat least two. However, these references are not intended to confer anyorder in time, structural orientation, or sidedness (e.g., left orright) with respect to a particular feature.

In accordance with the subject invention, the following particularlydescribed examples are intended to be illustrative only since numerousmodifications and variations therein will be apparent to those skilledin the art. As used in the specification and in the claims, the singularfor “a,” “an” and “the” include plural referents unless the contextclearly dictates otherwise.

With reference to the attached figures, which show certain embodimentsof the subject invention, it can be seen in FIG. 1A that one embodimentcomprises, in general, a valve body 100 having an upper seat 110, alower seat 130, a valve gland, or stem seal gland, 150, a centralthrough-hole 170, and a bore 190. Within the through-hole, a valve stemassembly 200 is seated that includes a valve stem 300, a lower bearingcup 400, an upper bearing 500, and a stein seal 600, each configured tobe operably installed within the through-hole such that the valve stem300 can be operable attached to a ball valve 900 (not shown) positionedwithin the bore 190. For literary convenience, the description of theembodiments of the subject invention will be made with reference to theproximal end 50 and the distal end 75, which are shown positionally onthe Figures for reference purposes.

Most valve body 100 configurations include a bore 190 for containing avalve ball and a through-hole for containing the valve stem assembly 200that can have an operable contact with the valve ball. In general, avalve ball has a central passage or port for conducting flow between thetwo open ends of the bore. There are several types of valve balls,including, but not limited to, full port, reduced port, and V-port,which are all known to those with skill in the art. Further, there areseveral types of valve bodies known to those with skill in the art,including, but not limited to, single body, three piece body, splitbody, top entry and welded. One embodiment of the valve stem assemblythat will be disclosed herein utilizes a single body valve constructionwith a full port valve ball. However, it should be understood thatsubstitution of alternative valve bodies and/or valve balls, other thanthose specifically exemplified herein, are contemplated to be within thescope of the herein disclosed embodiments of the subject invention.

The through-hole 170 can be defined as that volume between the upperedge 105 and the lower edge 135, examples of which are shown in FIGS.1A, 4A-4B, and 8A-8B. In a particular embodiment, the diameter of thethrough-hole is between 0.554 inches and approximately 0.558 inches, atthe portion of the through-hole having the smallest diameter. In aspecific embodiment, the diameter of the through-hole is approximately0.556 inches, at the portion of the through-bore having the smallestdiameter. In the embodiment shown in FIG. 1A, the portion of thethrough-hole having the smallest diameter can be referred to as themidsection 331. Surrounding the through-hole 170 there can also be anupper seat 110, a stem seal gland 150 that is contiguous with the upperseat, and a lower seat 130. An example of this embodiment can be seen inFIGS. 1A and 4B. The details of the through-hole will be discussed belowin relation to the lower bearing 400, upper bearing 500, and stem seal600 mated therewith.

Positioned collinearly with the through-hole is a valve stem 300. Thevalve stern can be an elongated rod having a first narrow end 310, amedial sealing area 330 supported by one or more seals, a head 350, andsecond narrow end 370. In the embodiment shown in FIG. 1A, the first end310 has a portion that is narrow for interconnecting with a handle andthe second end has a portion that is narrow for allowing interconnectionwith the ball. In specific embodiments, ends 310 and 370 need not benarrow, but can have a variety of shapes and sizes that allow the valvestem to be inserted into the through-hole without passing all the waythrough in at least one orientation. FIGS. 3A, 3B, and 3C illustrate onevalve stem assembly that can be utilized with embodiments of the subjectinvention. In this embodiment, the valve stem 300 is sufficiently longenough to allow the first end 310 to extend past the upper edge 105 andsecond narrow end 370 to extend past the lower edge 135. In otherspecific embodiments, the first end 310 need not extend past the upperedge 105, and an interconnection with a handle for rotating the valvestem about a longitudinal axis of the valve stem without the need forthe first end 310 to extend past the upper edge 105. Likewise, inspecific embodiments, the second end 370 need not extend past the loweredge 135, and an interconnection can be made between the valve stem andball of the ball valve that allows the ball to be rotated about thelongitudinal axis of the valve stem by rotating the valve stem about thesame longitudinal axis. In a specific embodiment, the valve stem isbetween approximately 2.0 inches and 2.2 inches in total length from thedistal end 75 to the proximal end 50 and can have a diameter of between0.50 inches and 0.55 inches. In a more specific embodiment, the valvestein is approximately 2.145 inches in total length from the distal end75 to the proximal end 50 and can have a diameter of approximately 0.548inches. Advantageously, the diameter of the valve stem in this specificembodiment can reduce stretching of the stem seal and can contribute toachieving an ideal stem seal compression of 15%, as will be discussedbelow. In a specific embodiment, the dimensions of the valve stem andstem seal gland are such that a pre-loading compression factor of 10-20%is achieved for the stem seal, where after loading, e.g., applying avacuum in the bore 190, the compression factor increases to create abetter seal. In further specific embodiments, the pre-loadingcompression factor is in the range 12-18%, and/or the range 14-16%.

In one embodiment, the first narrow end 310 includes ridges, nibbs,teeth, threads or similar projections that are compatible with at leastone tightening component 20. In a specific embodiment, the first narrowend 310 has threads 311 to accommodate at least one compatibly threadedtightening component 20 that can be screwed onto, or otherwise engagedwith, the complete valve stem assembly 200 for compressing andmaintaining pressure on the components to ensure a leak-proof seal. Sucha threaded tightening component 20 can comprise any of a variety ofdevices known to those with skill in the art. For example, a tighteningcomponent 20 can include a typical hex or square nut, a prevailingtorque lock nut (frequently used in high temperature applications), wingnut, locking nut or any similar device. In a specific embodiment, thethreading on the first narrow end 310 extends for a length ofapproximately 1.250 inches from the distal end 75.

Alternatively, a tightening component can comprise a ratchet-likeconfiguration, known to those with skill in the art. In this embodiment,a pawl nut or flange can be engaged with one or more teeth or ridges onthe first narrow end 310. Pushing the pawl nut onto the first narrow end310 causes it to engage with the teeth, which are slanted to preventbackward motion of the pawl nut. A person with skill in the art would beable to devise any of a variety of methods and devices for compressingand maintaining pressure on the valve stem assembly components of theherein described embodiments of the subject invention. Such variationsare contemplated to be within the scope of the embodiments of thesubject invention. Examples include, but are not limited to, a cotterpin and/or a tapered stem.

In a further embodiment, the circumferential shape of the first narrowend is such that it can be operably connected to an actuator, handle, orlever capable of turning the valve stem. It is well known in the art,that it is the turning, or rotating, of the valve stem about alongitudinal axis of the valve stem that turns the ball so as to controlthe flow through the ball valve. Oftentimes, the turning of the valvestem is performed with the use of a handle or lever operably attached tothe first narrow end to provide torque. To facilitate this, the shape ofthe first narrow end can be such that it interdigitates, or otherwiseinterconnects, with the attachment mechanism of the handle or lever, notunlike a wrench and nut combination. In one embodiment, at least aportion of the first narrow end 310 has a face 320. In a more particularembodiment, at least a portion of two opposite sides of the first narrowend 310 incorporates a face 320, as seen, for example in FIGS. 3A and3B. In alternative embodiments, at least a portion of more than twosides comprise flat faces 320. In one embodiment, the one or more flatfaces 320 can be cooperatively-engaged with a handle or lever. In aspecific embodiment, each flattened side is approximately 0.920 inchesin length from the distal end 75 of the first narrow end. In a furtherspecific embodiment, at least a portion of the first narrow end, nearestthe medial sealing area 330 remains circular, as seen in FIGS. 3A-3C,which can ensure adequately engagement with the tightening component 20.

The medial sealing area 330 is, in one embodiment, that portion of thevalve stem 300 that is positioned within the through-hole 170 andencircled by at least some portion of each of the lower bearing 400,upper bearing 500, and the stem seal gland 150, when the valve sternassembly 200 is fully constructed. The portion of the valve stem thatmatches up with the stem seal gland can be referred to as the stem glandsection of the valve stem, the portion of the valve stem that matches upwith the body midsection can be referred to as the stem midsection, theportion of the valve stem that matches up with the lower seat of thevalve body can be referred to as the head, and the portion of the valvestem that matches up with the upper seat can be referred to as the stemupper section. The diameter of the medial sealing area can vary, ofcourse, depending upon several factors, including, but not limited to,the size of the through-hole, location of the bearings and the stem sealgland, type of sealing surface, and other factors that would be known tothose with skill in the art. In one embodiment, the medial sealing areahas a length of between 0.40 inches and 0.50 inches and a diameter ofbetween 0.53 inches and 0.55 inches. In a specific embodiment, themedial sealing area has a length of approximately 0.450 inches and adiameter of approximately 0.5484 inches.

In a further embodiment, the lower bearing 400, upper bearing 500, andstem seal 600 encircle and can be, at least partially, in contact with asealing surface 335 on the exterior of the medial sealing area. In analternative embodiment, lower bearing 400, the upper bearing 500, andstem seal 600 encircle the sealing surface 335, but only the stem sealis in full contact around the entire circumference of the sealingsurface. The sealing surface can be configured with any of a multitudeof one or more textures or finishes that can engender it with adequatesealing capabilities. A person with skill in the art would be able todetermine a suitable texture or finish suitable for a sealing surface.In a specific embodiment, the sealing surface is a generally smooth,continuous surface, as shown, for example in FIG. 3A.

To assist with maintaining placement of the valve stem assembly withinthe through-hole 170 and compression of the valve stem assemblycomponents, the valve stem can further incorporate a head 350 that canbe nearer to the proximal end 50 of the medial sealing area. When thevalve stem assembly is constructed, the head can be positioned withinthe lower seat 130 of the valve body 100. FIG. 1A shows an example ofthis arrangement. In one embodiment, the outer diameter of the head islarger than the outer diameter of the medial sealing area 330. By thehead of the stem having an outer diameter than a diameter of at least aportion of the through-hole in at least one direction, the head preventsthe stem from passing through the through-hole in at least thatdirection. In a further embodiment, the head has a circular outercircumference. However, a person with skill in the art would understandthat the head can have any of a variety of outer circumferential shapesincluding, but not limited to, oval, square, triangular, rectangular, orany other polygonal shape. Examples of various embodiments are shown inFIGS. 1A, 8A, and 8B. When the tightening component 20 is applied to thefirst narrow end 310, the head 350 can exert a counter force that canmaintain the position of the valve stem assembly 200 within thethrough-hole 170 and assist with compression of the valve stemcomponents. The dimensions of a head can be variable depending upon avariety of factors that are known to those with skill in the art,including, but not limited to, the circumferential shape of the head,the valve stem material, the amount of compression to be applied to thevalve stem components, the dimensions of the second narrow end 370,discussed below, and other factors. In a particular embodiment, the headhas a circular circumference with an outer diameter of between 0.70inches and 0.72 inches and a length from the distal end 75 to theproximal end 50 of between 0.110 inches and 0.115 inches. In a specificembodiment, the head has a circular circumference with a diameter ofapproximately 0.715 inches and a length from the distal end 75 to theproximal end 50 of approximately 0.113 inches.

Following the head is a second narrow end 370 located at the mostproximal end 50 of the valve stem. The second narrow end 370 can engagewith a slot, groove, channel, or other opening on the ball valve andfacilitates turning of the ball valve when an actuator that operablyconnected to the first narrow end 310 is turned. The second narrow endcan have any of a variety of shapes or configurations that arecompatible with slot or groove on a ball valve, including slide-in orinterlocking connections. In specific embodiments, portions of, or allof, the second narrow end 370 can extend wider than the head 350extends. In further specific embodiments, the head 350 and second narrowend 370 are shaped such that the distal end 75 of the valve stem 300 canbe inserted into the central through hole 170 from the proximal end andpass through and exit the distal end of the central through hole 170. Aperson with skill in the art, having benefit of the subject application,would be able to determine an appropriate configuration for the secondnarrow end. Any and all such variations thereof are contemplated to bewithin the scope of the various embodiments of the subject invention.

In one embodiment, the second narrow end 370 is, in general, aprojecting tab that extends from the proximal end 50 of the head 350,for example, as shown in FIGS. 3A and 3C. In this embodiment, the shapeof the second narrow end 370 allows it to engage with a slot within aball valve. As such, it should be understood that the dimensions of thesecond narrow end 370 can be variable, depending upon factors that areapparent to those with skill in the art. In one particular embodiment,the second narrow end 370 has a length from the distal end 75 to theproximal end 50 of between 0.30 inches and 0.35 inches, a total width Wacross the head of between 0.70 inches and 0.72 inches, and a thicknessof between approximately 0.150 inches and approximately 0.155 inches.This embodiment can be modified to create another embodiment having athickness between 0.250 inches and 0.350 inches. In a more specificembodiment, an example of which is shown in FIGS. 3B-1 and 3C, thesecond narrow end 370 has a length from the distal end 75 to theproximal end 50 of approximately 0.332 inches, a total width W acrossthe head of approximately 0.715 inches, and a thickness T ofapproximately 0.153 inches. This embodiment can be modified to have athickness T of approximately 0.305 inches.

As mentioned above, turning of the actuator operably attached to thefirst narrow end 310 controls flow through the ball valve. The actuatoris often, but not necessarily, an elongated handle or lever mechanismthat has a portion thereof shaped to operably attach to the first narrowend 310 of the valve stem 300. The actuator can be manually orpneumatically or electropneumatically controlled. In one embodiment, thealignment of the first narrow end, with regard to the second narrow end,permits the actuator to be attached so that, when the port is alignedwith the open ends of the valve, allowing flow, the actuator is alsoinline or generally parallel with the valve. This can allow the positionof the valve to be easily determined by visual inspection. Conversely,when the actuator is turned 90°, to be generally perpendicular with thevalve, the port is also turned and effectively closed, as indicated bythe position of the actuator.

As mentioned above, the valve stem 300 can be positioned within athrough-hole 170 within the valve body 100. Surrounding the through-hole170 there can be one or more secondary bores into which differentsealing components can be seated to prevent leakage through thethrough-hole. In one embodiment, these secondary bores can include anupper seat 110, a lower seat 130, and a stem seal gland 150. In afurther embodiment, the valve assembly 200 includes the valve stem andthese sealing components that can be positioned within their respectivesecondary bores.

Starting from the proximal end 50 of the through-hole, it can be seen inthe embodiment shown in FIG. 1A that a lower seat 130 surrounds thethrough-hole and is contiguous with the bore hole 190. The head 350 ofthe valve stem can be seated within the lower seat. To promote properalignment and fit between the head and the lower seat, a lower bearingcup 400, such as that shown in FIGS. 5A-B, can be positioned between thehead and the lower seat, for example, as shown in FIG. 1A. Thus, thedimensions of the lower seat 130 can be such that the head and theassociated lower bearing cup can be placed therein with minimalclearance. This can aid in stabilizing the valve stem, reducing orpreventing contact between the head and the lower seat. In oneembodiment, the lower seat is generally circular with a diameter ofbetween 0.780 inches and 0.820 inches. In a specific embodiment, thelower seat is generally circular with a diameter of approximately 0.800inches.

In one embodiment, referring to FIGS. 5A and 5B, the lower bearing cup400 has a central valve stem opening 415 with an inner surface 410 thatsurrounds the medial sealing surface at or about where it meets the head350. The lower bearing cup 400 can then cover the distal end, or face,75 of the head 350 and extend down over the side, or edge, of the headtowards the proximal end 50, such that it fills, most, or substantiallyall, of the space between the outer surface of the side, or edge, of thehead and the inner surface of the lower seat. The lower bearing cup alsoprevents, or reduces, contact between the face of the head and the faceof the lower seat. In a further embodiment, the lower bearing cup 400extends beyond the proximal side 50 of the head. FIG. 1A shows anexample of a lower bearing cup 400 positioned around the head 350 withinthe lower seat 130. FIGS. 5A and 5B illustrate an embodiment of a lowerbearing cup 400 that can be utilized in accordance with the subjectinvention, as described. In this embodiment, the lower bearing cup iscircular. However, as mentioned above, the circumferential shape of thehead 350 can be any of a variety of circumferential shapes including,but not limited to, oval, square, triangular, rectangular, or any otherpolygonal shape. Therefore, it should be understood that the lowerbearing cup 400 can have any shape compatible with the shape of the headand the corresponding lower seat that ensures a snug fit.

The lower bearing cup 400 shown in FIG. 5B has a circular outer edgecontour and a circular inner edge contour, resulting in a uniformthickness of lower bearing cup positioned between the lower seat inneredge surface and the head outer edge surface, which allows the cup tofreely slide against the inner edge surface of the lower seat and theouter edge surface of the stem head. In other embodiments, the lowerbearing cup can have a non-circular outer edge contour, which matches asimilar inner edge surface contour of the lower seat, and a circularinner edge surface so as to allow the outer edge surface of the head tofreely slide with respect to the inner edge surface of the lower bearingcup while maintaining the relative position of the outer edge surface ofthe lower bearing cup and the inner edge surface of the lower seat.Conversely, the lower bearing cup can have a non-circular inner edgecontour, which matches a similar outer edge contour of the head, and acircular outer edge contour so as to allow the inner edge surface of thelower seat to slide freely with respect to the outer edge surface of thelower bearing cup while maintaining the relative position of the outeredge surface of the head and the inner edge surface of the lower bearingcup. The non-circular contours can be selected from a variety of shapessuch as polygonal, square, rectangular, hexagonal, or any other shapewhich would be apparent to one skilled in the art. Preferably, at leastthe outer edge contour or the inner edge contour of the lower bearingcup is circular to allow the valve stem to rotate while maintainingproper valve stem alignment within the through hole.

In a preferred embodiment, the lower bearing cup 400 prevents contactbetween the outer edge surface of the head and the inner edge surface ofthe lower seat, and prevents contact between the proximal face of thelower seat and the distal face of the head. In further embodiments, theinner surface of the lower seat has a curved surface as the surfacetravels from the proximal portion of the lower seat to the distalportion. In such embodiments, examples of which are shown in FIGS. 8Aand 8B, the lower bearing cup prevents more than a certain amount oflateral, or radial, movement of the head toward the inner edge of thelower seat under normal operating conditions and prevents more than acertain amount of longitudinal movement of the valve stem toward theinner edge of the lower seat in a direction parallel to the longitudinalaxis of the valve stem under normal operating conditions.

Referring to FIGS. 7A-7F, a variety of embodiments of the subjectinvention are shown, with some modifications to the embodiment shown inFIG. 1A. FIGS. 7A-7F do not show the lower bearing cup. FIG. 7A shows anembodiment where the upper seat is removed or greatly reduced in size.The upper bearing, not shown, can be inserted between the upper sectionof the valve stem and the upper seat section of the valve body, eitherby reducing the diameter of the upper section of the valve stem wherethe upper bearing is located or by having the diameter of the upper seatsection of the valve body enlarged to make room for the upper bearing.As with all of the embodiments shown in FIGS. 7A-7F, the upper bearingprevents contact between the upper section of the valve stem and theupper seat portion of the valve body, the lower bearing cup preventscontact between the head and the lower seat, and the lower bearing cupin combination with the upper bearing prevents contact between the valvebody midsection and the valve stem midsection. In FIG. 7A, the valvebody midsection is located between the stem seal gland and the lowerseat.

FIG. 7B shows an embodiment where the upper bearing forms a top surfaceof the stem seal gland and the upper bearing has a constant outerdiameter. FIG. 7C is similar to FIG. 7B, and shows the fasteningcomponent can be sunk into the valve body. In a specific embodiment, theentire fastening component can be at or below the upper edge 105 of thevalve body. FIG. 7D shows an embodiment where the upper bearing has aportion with a larger diameter that is above the upper seat. FIG. 7Eshows an embodiment where the fastening component is sunk into the upperseat. In a specific embodiment, the entire fastening component can be ator below the upper edge 105. In FIGS. 7B-7E, the portion of the upperbearing that extends down and forms the upper surface of the stem sealgland also limits lateral motion, in a direction perpendicular to thelongitudinal axis of the valve stem, of the valve stem toward the innersurface of the stem seal gland and the inner edge surface of the upperseat.

FIG. 7F shows an embodiment where a portion of the upper bearing formsan upper surface of the stem seal gland and the upper bearing limits thelateral motion of the valve stem toward the inner edge surface of theupper seat by the upper bearing contacting the upper section of thevalve stem and the inner edge surface of the upper seat. FIG. 7E showsan embodiment where the valve body midsection forms the inner edgesurface of the stem seal gland, the lower bearing cup forms the lowersurface of the stem seal gland, and the upper bearing forms the uppersurface of the stem seal gland. Various features of FIGS. 1A and 7A-7Ccan be combined together to create additional embodiments.

In various specific embodiments, the lower bearing cup and the upperbearing prevent contact between the valve stem and the valve body, limitlateral movement of the upper section of the valve stem to the valvebody, limit lateral movement of the head relative to the lower seat, andmaintain desired spacing between the lower surface of stem seal glandand stem gland portion of valve in order to control stem seal extrusionthrough same space when the pressure in the bore is below the pressureabove the valve body, and also controls spacing between the uppersurface of the stem seal gland and the stem gland section of the valvestem in order to control stem seal extrusion through the same space whenthe pressure in the bore 190 is above the pressure above the valve body.

In further embodiments, the shape of the upper bearing and the upperseat can vary much in the same way as the shape of the lower bearing cupand the lower seat, respectively, such that the upper bearing limitslateral movement of the upper section of the valve stem, and inembodiments where needed, in conjunction with the fastening componentand the face of the upper seat, prevents longitudinal movement of thevalve stem toward the bore 190.

Another term that can be used for lateral movement of the valve stemrelative to the upper seat and/or relative to the lower seat is yawing,which is known in the art. Other terms for through-hole, upper seat, andlower seat are through bore, counter bore, and back spot face,respectively, which are known in the art.

In a preferred embodiment, the cross-sectional shapes of the stein sealgland, stem gland section, stem midsection, and the body midsection areall circular, which enhances stem seal sealing and limits stem sealextrusion under vacuum pressures in the bore, and in a further preferredembodiment the section of the valve body that forms the upper surface ofthe stem seal gland also has a circular cross-sectional shape.

A lower bearing cup 400 can include any of a diversity of materials. Ina specific embodiment, the lower bearing cup made of a“PolyEtherEtherKetone” (PEEK) material. The upper bearing can also bemade from a number of materials known in the art, such as PEEK, whichcan slidably contact the surface of the valve stem and the upper seat,and allow the surface of the valve stem and/or the surface of the valvebody to slidably contact the upper bearing without galling, or withreduced galling, the surface of the valve stem and/or valve body,respectively. It is well-understood by those with skill in the art thatthe choice of which one or more material(s) to use for the lower bearingcup can depend upon several factors. Among the factors to consider are,for example, the expected application of the ball valve, which caninclude consideration of the environmental conditions that the valveassembly would be expected to encounter, the overall dimensions,compatibility with materials of surrounding components, thecharacteristics of the material, as well as other factors. Environmentalconditions can affect a material's expansion, contraction, stress point,contact with surrounding components and other factors that would beknown to those with skill in the art. Such factors can affect theability of the lower hearing cup to provide stabilization and to preventgalling between the valve stem and the valve seat. A person with skillin the art having benefit of the subject application would be able todetermine which one or more materials would be suitable for a lowerbearing cup. Thus, the substitution of materials other than thosespecifically exemplified herein is also contemplated to be within thescope of the embodiments of the subject invention.

In one particular embodiment, the lower bearing cup is generallycircular, such as shown, for example, in FIG. 5A. In a furtherparticular embodiment, the diameter of inner surface 410 is between0.550 inches and 0.560 inches. In a specific embodiment, the diameter ofthe inner surface 410 is approximately 0.553 inches. The diameter of theinterior surface 420 that comes in contact with the head can be between0.70 inches and 0.72 inches. In a specific embodiment, the interiorsurface 420 is approximately 0.718 inches. In another embodiment, theinterior surface 420 is approximately 0.715 inches. The diameter of theexterior surface 430 that is in contact with the lower seat 130 can bebetween 0.790 inches and 0.800 inches. In a further specific embodiment,the diameter of the exterior surface 430 is approximately 0.798 inches.In a further specific embodiment, the thickness 450 of the lower bearingcup is approximately 0.032 inches. Advantageously, the dimensions of thespecific embodiment, in conjunction with the use of PEEK for the lowercup material can significantly: 1. stabilize the valve stem by reducinglateral movement of the valve stem, and 2. reduce galling between thevalve stem and the valve body.

Proceeding towards the distal end 75 of the through-hole, in a furtherembodiment, the next sealing component is a stem seal 600 located withina stem seal gland 150 (referred to hereafter as the gland). Thisembodiment is also illustrated in FIG. 1A. The use of stem seals assealing components is well-known in the art. Typically, but necessarily,a stem seal is a mechanical gasket in the shape of a torus. That is, aloop of an elastomeric material with a disc-shaped cross-section. FIG. 6shows one embodiment of such a stem seal. Usually, a stem seal isdesigned to be seated within a groove and compressed between two or moreparts, creating a seal at the interface. They are commonly used instatic or dynamic applications where there is relative motion betweenthe parts and the stem seal, such as the valve stem assembly disclosedherein.

The factors that can be considered by those skilled in the art withregard to the choice of materials for each of the components of thevarious embodiments of the subject invention have been discussed aboveand are reasserted here with regard to the stem seal. Further, thedimensions utilized for a stem seal can also vary depending upon thesame, similar, or different factors. Of particular concern with regardto various embodiments is the expansion volume necessary in the gland150 to ensure sufficient sealing without undesirable extrusion and orgalling of the stem seal. A further concern is the ability of the stemseal to provide sufficient sealing capability at room temperature, aswell as elevated temperatures that the ball valve will likely encounterduring extending use or during certain applications. As such, thedimensions of the gland can be particularly relevant with regard to thestem seal expansion capabilities. Ideal compression of the stem sealwithin the gland can facilitate an adequate seal and reduce or eliminatestem seal galling. In a specific embodiment, ideal stem seal compressionis approximately 15%. In a further embodiment, the stem seal compressionis in the range 10 to 20%, 12 to 18%, and/or 14 to 16%.

In one embodiment, the gland 150 is a circular bore around thethrough-hole into which the stem seal is placed to encircle the valvestem 300 at the medial sealing area 330. It should be understood thatthe dimensions of the gland will vary depending upon the size and typeof stem seal utilized. The applicants anticipate that such variationsare within the scope of the embodiments of the subject invention. In afurther embodiment, the diameter of the gland is between 0.780 inchesand 0.784 inches. In a specific embodiment, the diameter of the gland isapproximately 0.782 inches. As mentioned above, the diameter of thevalve stem can be between 0.546 inches and 0.550 inches. In anotherembodiment, the diameter of the valve stem can be between 0.540 inchesand 0.550 inches. In a specific embodiment, the diameter of the valvestem is approximately 0.548 inches. In specific embodiments of the valvestem, the clearance between the valve body 100 and the valve stem 300 islimited to no more than 0.005 inches, or limited to no more than 0.007inches, which minimizes the risk of stem seal extrusion. Further, whenutilized with the above-disclosed specific embodiment of the valve stemhaving a medial sealing area 330 diameter of approximately 0.548 inches,the stem seal experiences minimal stretching and achieves idealcompression during maximum expansion. Advantageously, the specificembodiments of the subject invention disclosed herein allow a lubricatedstem seal of practically any suitable material to be utilized within thegland of the valve stem assembly. Some non-limiting examples of stemseals that can be utilized with the specific embodiments disclosedherein are the Viton® fluoroelastomer, Dupont Kalrez® 8575 series, orthe Dupont Kalrez® 4079 series or any other type of AS568-207 size.

Proceeding still further towards the distal end 75 of the through-hole170, the final component is an upper bearing 500 that can be operativelyengaged with an upper seat 110. The upper seat 110, similarly to thelower seat 130, can surround the through-hole. In a particularembodiment, the upper seat 100 is circular. As seen in the example shownin FIG. 1B, the most proximal end 150 of the upper seat is contiguouswith the stem seal gland, while the distal end 75 of the upper seatopens at the distal end of the valve body to define the upper edge 105.In a further embodiment, the first narrow end 310 extends proximally andpast the upper edge 105 of the upper seat 110.

An upper bearing 500 can be cooperatively-engaged with the upper seat110. In general, the upper bearing 500 can be a washer-like inserthaving a valve stem opening 515 through which the first narrow end 310can protrude, as shown, for example, in FIGS. 1A and 2A-2B. In oneembodiment, the distal end 75 of the upper bearing 500 is substantiallyflat, particularly near the valve stem opening 515 to benefit thetightening component 20. In an alternative embodiment, the distal end 75of the upper bearing 500 has one or more structures or features thatassist the tightening component, such as, for example, ridges, nibs,depressions, or other features that can engage with the tighteningcomponent to maintain the position of the valve stem and compression ofthe valve stem assembly. The upper bearing can be beneficial instabilizing the distal end 75 of the valve stem and limiting lateralmovement thereof.

Specific embodiments do not have an upper seat, but, rather, have thestem seal gland extend to the upper edge and a washer positioned incontact with the upper edge to also push on the stem seal. In anotherembodiment without an upper seat, the stem seal gland can extend intothe wall of the central through hole and the stem seal can be positionedin the gland prior to inserting the valve stem.

The factors that can be considered by those skilled in the art withregard to the choice of materials for each of the components of thevarious embodiments of the subject invention have been discussed aboveand are restated here with regard to the upper bearing. In a specificembodiment, the upper bearing comprises a “PolyEtherEtherKetone” (PEEK)material. Further, the circumferential shape of the upper bearing canvary depending upon the circumferential shape of the upper seat 110. Itcan be advantageous, but not necessary, for the circumferential shape ofthe upper bearing and the upper seat to be sufficiently the same. In aspecific embodiment, the upper seat 110 and the upper bearing havecircular circumferential shapes. In further specific embodiments, thediameter of the upper seat is approximately 2.375 inches, or isapproximately 1.375 inches, with a depth from the upper edge 105 to thestart of the stem seal gland is approximately 0.075 inches, orapproximately 0.135 inches, respectively.

In a further embodiment, the proximal side 50 of the upper bearing 500includes a step 520, as seen, for example, in FIGS. 2A and 2B, that candescend into the stem seal gland, when the upper bearing 500 is placedin the upper seat 110. FIG. 1A illustrates this embodiment. When thestep is positioned within the stem seal gland 150, it mimics thefunctionality of an enclosed stem seal groove. Advantageously, the step520 can limit axial movement of the stem seal, to ensure that it doesnot extrude onto the threads 311 of the valve stern, and furtherstabilize the distal end 75 of the valve stem. A further advantage tothe use of a step 520 is that it can significantly reduce manufacturingcosts and complexity.

The depth of the step, which can determine how far it descends into thestem seal gland, can depend upon, among other factors, the dimensions ofthe stem seal gland itself. Further, the step depth 525 can beconsistent across the entire diameter. In other words, the proximal side50 of the step 520 can be generally flat. In this embodiment, the stepdepth 525 is between 0.030 inches and 0.040 inches. In a specificembodiment, the step depth 525 is approximately 0.035 inches. But,alternative embodiments can employ a step 520 wherein the proximal sidehas one or more slanting surfaces or indentations to compensate for stemseal expansion. In one alternative embodiment, the proximal side of thestep has a convex curvature or angle, such that the step descendsfurther into the stem seal gland nearer the valve stem opening 515.

Certainly, the ability of the step 520 to interdigitate with the stemseal gland 150 can be facilitated if their circumferential shapes arecompatible. As discussed previously, and restated here, thecircumferential shape of the stem seal gland and the stem seal can varydepending upon a variety of factors known to those with skill in theart. Thus, the circumferential shape of the step 520 can also bevariable. In a specific embodiment, the circumferential shape of thestep is circular, so as to be compatible with specific embodiments ofthe stem seal and stem seal gland disclosed previously herein. Inparticular embodiments, the diameter of the step is between 0.780 inchesand 0.784 inches, or between 0.7 inches and 0.8 inches. In furtherspecific embodiment, the diameter of the step is approximately 0.782inches.

The ball valve design disclosed herein is an improvement over currentball valve designs and is useful in a wider variety of applications. Theimproved valve stem design allows it to function equally well in a widerange of temperatures, depending on stem seal material selection. In oneembodiment, temperatures range from 22° C. to 200° C. In anotherimplementation temperatures range from 200° C. to 300° C. It isanticipated that higher temperature limits will be soon made availableas new stem seal materials are made available and these would beincorporated into the design contemplated herein. Specific embodimentspertain to ball valves that are used to maintain a seal between one end,such as the proximal end, of the valve body 100 and the other end, suchas the distal end, of the valve body. In a specific embodiment, theproximal end of the valve body, or central through hole, is at vacuumpressure and the distal end of the valve body, or central through hole,is at atmospheric pressure. In further specific embodiments, the vacuumpressure at the proximal end of the valve body is in the range from 760Torr to 10⁻¹² Torr, in the range from 760 Torr to 10⁻⁸ Torr, and in therange from 10⁻³ Torr to 10⁻⁸ Torr. The improvements in stem sealcompression seen in this disclosed new design can reduce extrusion andsubsequent undesirable wear on the stem seal. Thus, the life of thevalve (number of open/close cycles) can be increased. The further use ofupper and lower bearings, as disclosed herein, can stabilize the valvestem, reduce lateral and axial movement, and eliminate use of copper orother types of metallic washers. In a specific embodiment, an evacuationhole, such as in the ball of the ball valve, can be incorporated.

All patents, patent applications, provisional applications, andpublications referred to or cited herein are incorporated by referencein their entirety, including all figures and tables, to the extent theyare not inconsistent with the explicit teachings of this specification.

It should be understood that the examples and embodiments describedherein are for illustrative purposes only and that various modificationsor changes in light thereof will be suggested to persons skilled in theart and are to be included within the spirit and purview of thisapplication.

The embodiments of the subject invention have been described herein inconsiderable detail, in order to comply with the patent Statutes and toprovide those skilled in the art with information needed to apply thenovel principles, and to construct and use such specialized componentsas are required. However, it is to be understood that the invention canbe carried out by specifically different equipment and devices, and thatvarious modifications, both as to equipment details and operatingprocedures can be effected without departing from the scope of theinvention itself. Further, it should be understood that, although thepresent invention has been described with reference to specific detailsof certain embodiments thereof, it is not intended that such detailsshould be regarded as limitations upon the scope of the invention exceptas and to the extent that they are included in the accompanying claims.

What is claimed is:
 1. A valve, comprising: a valve body, the valve bodyhaving a through hole that passes through a wall of the valve body froman outer wall surface to an inner wall surface, wherein a proximal endof the through hole is an opening in the inner wall surface and a distalend of the through hole is an opening in the outer wall surface, whereinthe through hole comprises: a body gland section positioned proximal tothe outer wall surface, wherein the body gland section has a circularcross-section having a first radius, a body midsection having a circularcross-section having a second radius, and a lower seat positionedbetween the body midsection and the inner wall surface, wherein at leasta portion of the lower seat has a third radius, wherein the secondradius is smaller than the first radius, wherein the second radius issmaller than the third radius; and a valve stem; wherein the valve stemcomprises: a head proximate a proximal end of the valve stem, a stemmidsection having a circular cross-section, and a stem gland section,wherein at least a portion of the stem gland section has a circularcross-section, wherein the stem midsection is between the head and thestem gland section, wherein the valve body and the valve stem areadapted such that a distal end of the valve stem can enter the proximalend of the through hole and pass into the through hole such that atleast a portion of the head is in the lower seat, wherein at least aportion of the head has a head radius that is larger than the secondradius, wherein the head and the lower seat are adapted such that alower bearing cup can be positioned such that the lower bearing cupprevents contact between a head outer surface and a lower seat innersurface when the valve stem is fully inserted into the through hole,wherein the stem gland section and the body gland section are adaptedsuch that a stem seal can be positioned around the stem gland section soas to be in contact with a stein gland section outer surface around acircumference of the stem gland section and when the valve stem is fullyinserted into the through hole the stem seal is positioned in a stemseal gland, wherein the stem seal gland is formed by the stem glandsection outer surface, a body gland section inner surface, a proximalstem seal gland face, and a distal stem seal gland face, wherein theproximal stein seal gland face is a distal face surface of the bodymidsection, wherein when the valve stem is fully inserted into thethrough hole, the stem seal is positioned around the stem gland sectionso as to be in contact with the stem gland section outer surface arounda circumference of the stem gland section, the stem seal is positionedin the stem seal gland, and a pressure differential is applied between afirst region distal to the outer wall surface and a second regionproximal to the inner wall surface such that a first pressure of thefirst region is higher than a second pressure of the second region, afirst seal is created between the stem seal and the stem gland sectionouter surface and a second seal is created between the stem seal and thebody gland section inner surface, such that the pressure differentialbetween the first region distal to the outer wall surface and the secondregion proximal to the inner wall surface is maintained, wherein thefirst seal and the second seal are maintained as the valve stem isrotated about a longitudinal axis of the valve stem with respect to thevalve body.
 2. The valve according to claim 1, wherein the valve is aball valve.
 3. The valve according to claim 1, wherein the lower seathas a circular cross-section.
 4. The valve according to claim 1, whereinwhen the distal end of the valve stem enters the proximal end of thethrough hole and passes into the through hole such that at least aportion of the head is in the lower seat, the distal end of the valvestem extends past the outer wall surface.
 5. The valve according toclaim 1, wherein the head outer surface comprises a head face and a headouter edge surface, wherein the lower seat inner surface comprises alower seat face and a lower seat inner edge surface, wherein the lowerbearing cup prevents contact between the head face and the lower seatface and prevents contact between the head outer edge surface and thelower seat inner edge surface when the valve stem is fully inserted intothe through hole.
 6. The valve according to claim 5, further comprising:a lower bearing cup, wherein the lower bearing cup comprises a faceportion and an edge portion, wherein when the valve stem is fullyinserted into the through hole the lower bearing cup is positioned so asto prevent contact between the head face and the lower seat face and toprevent contact between the head outer edge surface and the lower seatinner edge surface, wherein the edge portion contains lateral movementof the head with respect to the lower seat.
 7. The valve according toclaim 6, wherein the edge portion keeps lateral movement of the headwith respect to the lower seat to below or equal to a maximum lateralmovement, wherein lateral movement above the maximum lateral movementleads to improper extrusion of the stem seal between the stem glandsection outer surface and the proximal stem seal gland face.
 8. Thevalve according to claim 7, wherein the head has a circularcross-section having a head radius, wherein the lower seat has acircular cross-section having the third radius, wherein the differencebetween the head radius and the third radius is less than or equal to athickness of the edge portion of the lower hearing cup plus the maximumlateral movement.
 9. The valve according to claim 2, further comprisinga ball, wherein the valve stem further comprises a protrusion extendingproximally from the head such that when the valve stem is fully extendedinto the through hole the protrusion extends proximally past the innerwall surface and engages the ball such that when the valve stem isrotated about a longitudinal axis of the valve stem the ball rotates.10. The valve according to claim 1, further comprising a means forsecuring the valve stein in place with the valve stem fully insertedinto the through hole.
 11. The valve according to claim 10, wherein themeans for securing the valve stem in place comprises: threads on athreaded portion of the valve stem, wherein the threaded portion of thevalve stem is distal to the stem gland section; and a componentthreadably engageable with the threads on the threaded portion of thevalve stem.
 12. The valve according to claim 1, wherein the through holecomprises an upper section having a circular cross-section having afourth radius, wherein the upper section is distal to the body sealgland section, wherein the fourth radius is the same as the secondradius, wherein a proximal face of the upper section is the proximalstem seal gland face.
 13. The valve according to claim 1, furthercomprising an upper bearing, wherein the upper bearing is positionedbetween the stem and the valve body at a position distal to the stemseal when the valve stem is fully inserted into the through hole and thepressure differential is applied, wherein the upper bearing incombination with the lower bearing cup prevents contact between thevalve stem and the through hole.
 14. The valve according to claim 13,wherein the through hole comprises an upper seat, wherein the upper seathas a radius at least as large as the second radius at each positionaround a circumference of the upper seat, wherein at least a portion ofthe upper bearing is positioned in the upper seat when the valve stem isfully inserted into the through hole.
 15. The valve according to claim13, wherein the upper bearing in combination with the lower bearing cupprevents contact between the valve stem and the through hole as thevalve stem is rotated up to 90 degrees about a longitudinal axis of thevalve stem.
 16. The valve according to claim 13, wherein at least aportion of a proximal face of the upper bearing is the proximal stemseal gland face.
 17. The valve according to claim 13, wherein the upperbearing comprises a main upper bearing body and a step at a proximal endof the upper bearing, wherein the step is positioned in the body glandsection when the valve stem is fully inserted into the through hole suchthat an outer edge surface of the step contacts a portion of an innerradial surface of the body gland section that is continuous with aninner radial surface of the stem seal gland, wherein a proximal face ofthe step is the distal stem seal gland face.
 18. The valve according toclaim 17, wherein the step in combination with the lower bearing cupprevents contact between a stem midsection outer surface and a bodymidsection inner surface.
 19. The valve according to claim 18, whereinthe step keeps lateral movement of the stem with respect to the bodygland section to below or equal to a maximum lateral movement, whereinlateral movement above the maximum lateral movement leads to improperextrusion of the stem seal between the stem gland section outer surfaceand the proximal stem seal gland face.
 20. The valve according to claim19, wherein the step has an annular cross-section having an inner stepradius and an outer step radius, wherein the difference between theinner step radius and a radius of a section of the stem that contactsthe step plus the difference between the first radius and the outer stepradius is less than or equal to the maximum lateral movement.
 21. Avalve, comprising: a valve body, the valve body having a through holethat passes through a wall of the valve body from an outer wall surfaceto an inner wall surface, wherein a proximal end of the through hole isan opening in the inner wall surface and a distal end of the throughhole is an opening in the outer wall surface, wherein the through holecomprises: a body gland section positioned proximal to the outer wallsurface, wherein the body gland section has a circular cross-sectionhaving a first radius, and a lower seat positioned between the bodygland section and the inner wall surface, wherein at least a portion ofthe lower seat has a second radius, wherein the second radius is largerthan the first radius; and a valve stem; wherein the valve stemcomprises: a head proximate a proximal end of the valve stem, and a stemgland section, wherein at least a portion of the stem gland section hasa circular cross-section, wherein the stem gland section is distal tothe head, wherein the valve body and the valve stem are adapted suchthat a distal end of the valve stem can enter the proximal end of thethrough hole and pass into the through hole such that at least a portionof the head is in the lower seat, wherein at least a portion of the headhas a head radius that is larger than the first radius, wherein the headand the lower seat are adapted such that a lower bearing cup can bepositioned such that the lower bearing cup prevents contact between ahead outer surface and a lower seat inner surface when the valve stem isfully inserted into the through hole, wherein the stem gland section andthe body gland section are adapted such that a stem seal can bepositioned around the stem gland section so as to be in contact with astem gland section outer surface around a circumference of the stemgland section and when the valve stem is fully inserted into the throughhole the stem seal is positioned in a stem seal gland, wherein the stemseal gland is formed by the stem gland section outer surface, a bodygland section inner surface, a proximal stem seal gland face, and adistal stem seal gland face, wherein when the valve stem is fullyinserted into the through hole, the stem seal is positioned around thestem gland section so as to be in contact with the stem gland sectionouter surface around a circumference of the stem gland section, the stemseal is positioned in the stem seal gland, and a pressure differentialis applied between a first region distal to the outer wall surface and asecond region proximal to the inner wall surface such that a firstpressure of the first region is higher than a second pressure of thesecond region, a first seal is created between the stein seal and thestem gland section outer surface and a second seal is created betweenthe stem seal and the body gland section inner surface, such that thepressure differential between the first region distal to the outer wallsurface and the second region proximal to the inner wall surface ismaintained, wherein the first seal and the second seal are maintained asthe valve stem is rotated about a longitudinal axis of the valve stemwith respect to the valve body.
 22. The valve according to claim 17,wherein the valve is a ball valve.
 23. The valve according to claim 21,wherein the head outer surface comprises a head face and a head outeredge surface, wherein the lower seat inner surface comprises a lowerseat face and a lower seat inner edge surface, wherein the lower bearingcup prevents contact between the head face and the lower seat face andprevents contact between the head outer edge surface and the lower seatinner edge surface when the valve stem is fully inserted into thethrough hole.
 24. The valve according to claim 21, wherein the lowerbearing cup provides the proximal stem seal gland face.